1. Field of the Invention
This invention relates to a dental instrument and, in particular, to a dental articulator useful for simulating and illustrating mendibular movement.
2. Brief Statement of the Prior Art
Advances in the design and construction of dental articulators have generally been directed towards greater and greater complexity of these instruments to achieve a closer simulation and long sought duplication of mendibular movements. Some recent attempts are illustrated in U.S. Pat. Nos. 3,478,431 and 3,769,708.
The increasing complexity of these instruments increases the cost as well as the delicacy of the instruments and precludes their use for many routine clinical applications where a semi-adjustable instrument, i.e., an instrument having a limited adjustment capability is desired.
The recent generation of dental articulator development has generally followed the Arcon type instrument in which the upper frame of the articulator carries a generally box-like fossa guide assembly of superior and, optionally, posterior and media wall guide elements which cooperate with respective ones of a pair of spaced-apart spherical condylar elements carried on the lower frame member. A common shortcoming of the designs of the prior Arcon articulators has been the absence of an effective, releasable latch mechanism to interlock the upper and lower frame members. Ideally, such a latch mechanism should be operative to interlock the frame members in both the closed and opened positions yet be releasable to permit separation of the frame members. Additionally, when the instrument is provided with medial wall adjustment capability providing for an immediate side shift, i.e., entirely lateral translation of the frame members, the latch mechanism should also serve to align the frame members in a centric position. Prior designs of interlock means for Arcon type instruments are shown in the magnetic interlock of U.S. Pat. No. 2,816,366 and the centric orienting mechanism shown in the aforementioned patent.
A recent design was marketed by Schazi Company under the name Occlusomatic which featured a mechanical lock between the upper and lower frame members. This design did not permit full opening of the frame members and its marketing has been discontinued.